Spermine Measuring Device Evaluation Protocol

Prostate cancer (PC) is highly prevalent worldwide and is currently the 3rd most commonly diagnosed prostate cancer in Hong Kong male population with more than 2000 new cases diagnosed per year. Depending on the clinical staging and also the patients' condition, different treatments, including curative surgery or radiotherapy, palliative androgen deprivation therapy, could be offered to patients and will good response. However, current there are only one biological marker, PSA, for the monitoring of the disease progress and treatment response. While PSA testing provided a reasonable assessment of the disease status and progress, it is an invasive blood test and maybe less convenience for some patients. Therefore, there is a need for exploring newer markers for the monitoring of the treatment response and disease progress is needed.

One example of such cancer biomarkers are natural polyamines. Interests on these analytes have been starting in 1971 when Russell reported a considerable increase of urinary polyamines such as putrescine (Put), spermidine (Spd) and spermine (Spm) in patients with various types of solid tumors and leukaemias. Afterwards, polyamine studies focusing on specific cancers continued, like cervical cancer, colorectal cancer and breast cancer, etc.

In our recent study, we have explored the potential roles of urinary polyamines as prostate cancer biomarkers were evaluated. Patients with prostate cancer (PCa), benign prostatic hyperplasia (BPH) patients and healthy controls (HC) showing PSA>4.0ng/ml were enrolled in the study. Their urine samples were obtained, and the urinary levels of Put, Spd, Spm were determined by ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometer (UPLC-MS/MS). Receiver operating characteristics (ROC) curve and Student's t- test were used to evaluate their diagnostic accuracies. Among the three biogenic polyamines, Spm had demonstrated a good diagnostic performance when comparing their levels in PCa patients with BPH patients (1.47 in PCa vs 5.87 in BPH; p<0.0001). The results were in accordance with transrectal ultrasound prostatic biopsy (TRUSPB) results, with an area under curve (AUC) value of 0.83±0.03. Therefore, urinary Spm could have a potential to serve as a novel PCa diagnostic biomarker, which in turn could help to address the limited sensitivity and specificity problem of serum PSA test. In our further work, we have confirmed that spermine is a good marker for the detection of prostate cancer and also showed good correlation with cancer grading.

However, the current measurement of spermine required the use of liquid chromatography (LCM) in laboratory, which might limit its clinical usage. Therefore, a simple spermine measuring device (SMD) has been designed for easier daily usage, such as simple cancer screening and also combined evaluation with serum PSA level. The SMD is a simple device, with automatic urine aspiration and also spermine level assessment. First about 30 cc urine will be freshly collected by a prepared collection device. Then the cap of the SMD will be removed and the aspiration tip of the device will be immersed into the urine specimen. After firmly pressed on the device, a small sample of urine will be aspirated into the SMD. The device will then automatically assess the urine spermine level. The result will then be read at a indicator window after about 5 minutes. If the level was below a pre-set cutoff, i.e. suggestive of having increase risk of prostate cancer, the indicator window will turn into red colour.

However, if the spermine level is higher than the cutoff value, i.e. low risk of having cancer, the indicator window will turn blue. However, the kit has not been validated in clinical urine sample. Therefore, we would like to perform an evaluation the accuracy of this SMD with the laboratory measured spermine level by LCM, as well as the pathology result from prostate biopsy.